Severance line construction for cartons



Sept. 15, 1964 1 w, OST A 3,148,824

SEVERANCE LINE CONSTRUCTION FOR CARTONS Filed Feb. 4, 1963 fnuerzl ons'rf/zamcw' Z0. Rafe? and C/LcZrZEJ 22/. .Vrzfurorzi United States Patent O3,148,824 SEVERANCE LINE CONSTRUCTION FOR CARTONS Thomas W. Foster,Chicago, and Charles W. Venturoni,

Glen Ellyn, 111., assignors to Container Corporation of America,Chicago, 111., a corporation of Delaware Filed Feb. 4, 1963, Ser. No.255,962 1 Claim. (Cl. 229-51) The present invention relates tofabricated paperboard products, such as foldable cartons, andparticularly relates to cartons and similar articles, formed ofpaperboard, having a weakened severance line or a severable tear-outarea in one or more panels or walls.

An object of the invention is to form a neat appearing and efficientform of weakened line in a wall or other panel which will remain intactup to the time of use and will permit the user of the paperboard item totear the paperboard along a severance line, or tear out a severable areain a single panel, or in one or more adjoining panels, without atendency of the edge portions shredding or peeling along the severededges.

A further object of the invention is to form in a paperboard panel aweakened severance line which is of particular advantage in a paperboardcarton or other paperboard product in which the line of severance isformed along a curve, as for example, when it is desired to tear out arounded contour section from a wall panel.

Additional and more specific objects and advantages of the inventionwill become apparent as the description proceeds.

In the drawings- FIGURE 1 is a perspective View of an erected foldingcarton formed with severance lines for removal of an oval dispensingopening;

FIGURE 2 is an enlarged, fragmentary perspective view of a section ofpaperboard having the improved severance line formed therein;

FIGURE 3 is a plan view of an enlarged fragment of paperborad similar toFIGURE 2;

FIGURE 4 is a fragmentary sectional view taken along line 4-4 of FIGURE3, and indicating the construction of cutting edge on a cutting tooldesigned to produce the severance line of the present invention; and

FIGURE 5 is a fragmentary vertical section taken along line 55 of FIGURE4.

According to known methods for cutting paperboard to produce a weakenedseverance line, a cutting tool is employed which has an interruptedcutting edge enabling it to form a series of short, aligned, spaced cutspassing through the board. While this creates a weakened line of tearsatisfactory for aifording easy access to the interior of a carton, orfor the removal of an area or strip of paperboard in other types ofconstructions, it is not satisfactory in certain situations. As anexample, if the paperboard, formed with such a weakened line, has arelatively strong and tough outer surface and tearing along such line iscommenced, the fibres, transverse to the line of cuts and in the spacestherebetween, tend to cling together sufiiciently to cause small stripsor shreds to form and produce peeling of the surface portions of theboard in the parts that are intended to remain after removal of the partto be discarded. This peeling occurs most frequently when the portion tobe removed from a panel has a curved contour and in which the path ofthe curve extends toward the extended axis of the portion of the panelto be removed. This tendency to peel is quite undesirable in foldingcartons to be used in the dispensing of household consumer items whereit is intended that the package will remain accessible for a period oftime while the contents are being used. In uses in which emphasis isplaced on the attractiveness of the package, any

shredding or peeling of the panel around the dispensing opening detractsfrom the appearance of the package and tends to create resistance to theproduct in the minds of the users.

According to the present invention, a series of short, primary cuts isformed to define the line of severance, such cuts extending completelythrough the paperboard and additional short, spaced cuts are formedintermediate the primary cuts and on the exterior surface of the board,such secondary cuts passing only part way through the paperboard.

Referring to the drawings, an erected carton is shown in which the topwall 1 and an adjoining wall 2 are formed with a tear-out area indicatedas a whole at 3 and comprising sections 4 and 5 in the respective wallsections 1 and 2. I

The paperboard from which the carton is made is shown in detail inFIGURE 2. The board is indicated as a whole at 6 and comprises a facingportion 7 and a main body portion 8. In usual practice the facingportion 7, which constitutes the outside of the sheet of board, isformed as a relatively dense, tough covering or liner for the weakerfiller or body portion 8. This liner portion, in practice, may be formedas an integral part of the sheet on a multi-cylinder paperboard machine.In a sheet having a thickness of .012 to .020 inch, the liner portionmay have a thickness of approximately .003 inch. The liner portion 7 maycomprise bleached sulphate pulp or the equivalent, and the fillerportion 8 may comprise a type of pulp formed of mixed papers andcommercially termed chip stock.

The liner portion 7, being dense and tough, provides a good printingsurface and has good resistance to abrasion and tearing.

The carton is cut and creased in flat blank condition on a cutting andscoring press. In order to form a satisfactory severance line a cuttingtool, the edge portion of which is indicated at 10, may be employed. Thecutting elements comprise a series of equi-length blade sections 11, 11between which are shallower blade sections 12, 12. The cutting tool iscontrolled so that the cutting edges of sections 11, 11 will passcompletely through the paperboard sheet to form primary cuts 11a, 11a,as indicated in FIGURE 4, and the cutting edges of the shallowersections 12, 12 will pass completely through the liner portion 7 of thesheet and may penetrate to a depth of approximately half way through thecomposite sheet, thus forming secondary cuts 12a, 12a.

By so cutting the liner portion of the sheet the fibres of this portionwhich extend transversely of the severance line will be cut and thus thetendency of the liner to shred and peel into the panel portions outsidethe area to be removed will be overcome. This is of particular advantagein assuring a clean tear along curved lines, such as those illustratedin the panel 2 in FIGURE 1. In this panel the section to be removed isoval and the direction of the tear, as it progresses, is inward towardthe longitudinal axis of the tear-out portion 3. As the tear-out portionis being severed along the curved lines in panel 2 there still remainssome uncut fibres between the adjacent ends of the primary cuts 11a,11a, but such uncut fibres are below the bottoms of the secondary cuts.Except for the secondary cuts the progressive upward pull along theedges of panel section 5 would tend to lift small portions of the fibresbetween the ends of the primary cuts and start the peeling of one ormore strips of the surface of the sheet in a direction approximately atright angles to the bottom edge of panel 2. This tendency would beincreased where the grain of the board is disposed transversely to thelengths of panels 1 and 2. By making the secondary cuts penetratesufficiently to pass entirely through the liner, the stronger fibres areout between the ends of the primary cuts 11a, 11a to prevent peeling,but, at the same time, a sufficient thickness of board remains intactbetween the primary cuts to assure that the removable panel will remainin place until lifting force is applied to remove it.

By so preparing paperboard cartons to provide for an easy tear-outsection and overcoming the tendency of peeling or shredding of thesurface of the panels adjoining, but outside the tear-out area, thecartons, when so constructed, are rendered more desirable for householduse. This is especially true in situations in which the carton is to beused as a dispensing container for extended periods. remain in a neatand attractive condition.

The present invention is not limited for use on cartons but isapplicable to other types of paperboard products in which it is desiredto provide tear lines for easy severance of panel sections, Accordingly,it is to be understood that limitations on the invention are intendedonly as specifically set forth in the appended claim.

In such case it is important that the carton What is claimed is:

A paperboard panel constructed with a thin integrally formed, toughfacing bleached sulphate or equivalent liner, such panel having aseverance line therein comprising a series of elongated, spaced,aligned, primary cuts passing entirely through the board and by a seriesof elongated, secondary cuts narrower than the primary cuts, alignedsymmetrically therewith, and located alternately therebetween, suchsecondary cuts extending only partially through the paperboard butentirely through said facing liner.

References Cited in the file of this patent UNITED STATES PATENTS2,189,431 Moore Feb. 6, 1940 2,769,588 Beck Nov. 6, 1956 3,021,002 GuyerFeb. 13, 1962 3,045,891 Alvarez July 24, 1962

